FischerBot

FischerBot is a two wheel robot, based on Arduino and equipped with sensors and motor control and mechanically build with parts from the fischertechnik® construction kit.

This may be one of the easiest way to build a robot with a complete custom design. You can buy fischertechnik® from ebay® and get motors, gears, switches, lights, etc. The best thing is, that you can try out many different robot designs. Just disassemble your current robot and build a new one!

Features:

• ATmega1284P microcontroller
• Soft power switch
• USB to serial interface through FT232RL
• Wireless serial connection through WiFly module (*)
• USB/WiFly serial can be programatically switched
• Piezo buzzer sound generation
• L293D motor driver for 2 motors
• 2 rotary encoders
• 2 LED lights
• 2 bumper switches
• I2C connector
• 3 ultrasonic distance sensors (SRF02) connected through I2C
• CMPS03 compass module connected through I2C
• ISP connector

(*) The pictures show the original version with an XBee module. WiFly modules are pin compatible with the XBee modules.

Wheel Rotary Encoders

The rotary encoders use a CNY70 reflective optical sensor and a disc consisting of black and white sectors. The CNY70 transistor is connected directly to the ATmega1284P port pins. This seems to work, but i have not fully tested the accuracy of this circuit.

Power Supply

Although i use a fischertechnik® Power Block in my robot design which can be equipped with 6 AA batteries, it is always better to use a LiPo pack to drive the robot, since they can deliver more current. In this case its a 2 cell 7,2V 2000 mAh LiPo.

Board and Schematics

This was my first PCB with a solder mask and silk screen ( Bungard laminate).
But this is a lot of work and i think it's only worthwhile if the PCB's are visible in the finished product.

Eagle files (Schematics and PCB) can be found in the project file down below.

GitHub

The source code for this project is hosted on GitHub: https://github.com/grappendorf/fischerbot